Wheel bearing apparatus is known that supports a vehicle wheel relative to a suspension apparatus. The wheel bearing apparatus includes a wheel speed detecting apparatus to detect a rotational speed of a wheel to detect the wheel speed to control the anti-lock braking system (ABS). Such a bearing apparatus generally has a wheel speed detecting apparatus with a magnetic encoder. The encoder has magnetic poles alternately arranged along its circumferential direction integrated in a sealing apparatus arranged between inner and outer members that contain rolling elements (balls or rollers). A wheel speed detecting sensor detects variations in the magnetic poles of the magnetic encoder according to the rotation of the wheel.
FIG. 5 is a representative example of such a wheel bearing apparatus for a driving wheel. The wheel bearing apparatus has an outer member 51. It is integrally formed, on its outer circumference, with a body (vehicle body) mounting flange 51b to be mounted on a knuckle (not shown). Its inner circumference includes double row outer raceway surfaces 51a and 51a. An inner member 56 has a wheel hub 52 and an outer joint member 55 of a constant velocity universal joint 61. The wheel hub 52 has a wheel mounting flange 53 integrally formed at one end. A plurality of hub bolts 54, to secure a wheel (not shown), is mounted equidistantly along the flange periphery. The outer circumference of the wheel hub 52 includes an inner raceway surface 52a corresponding to one of the double row outer raceway surfaces 51a and 51a. A cylindrical portion 52b axially extends from the inner raceway surface 52a. The outer joint member 55 is inserted into the cylindrical portion 52b of the wheel hub 52. The outer circumference of the outer joint member 55 includes another inner raceway surface 55a corresponding to the other of the double row outer raceway surfaces 51a and 51a. 
Double row rolling elements (balls) 57, held by cages 58, are rollably arranged between the outer raceway surfaces 51a and 51a and inner raceway surfaces 52a and 55a. In addition, seals 59 and 60 are mounted in opening portions of an annular space formed between the outer member 51 and the inner member 56 to prevent leakage of lubricating grease contained within the bearing. The seals 59, 60 prevent rain water or dusts from the outside entering into the bearing.
The outer joint member 55 forms part of the constant velocity universal joint 61. It includes a cup shaped mouth portion 62, a shoulder portion 63, forming the bottom of the mouth portion 62, and a hollow shaft portion 64 that axially extends from the shoulder portion 63. The shaft portion 64 has a spigot portion 64a fit into the cylindrical portion 52b of the wheel hub 52 and a fitting portion 64b at the end of the spigot portion 64a. 
An inner circumferential surface of the wheel hub 52 has a hardened irregular portion 65. The shaft portion 64 of the outer joint member 55 is fit into the wheel hub 52. The wheel hub 52 and the outer joint member 55 are integrally connected to each other via plastic deformation. The fitting portion 64b of the shaft portion 64 is expanded radially outward forcing the material of the fitting portion 64b to bite into the hardened irregular portion 65.
The seal 60, arranged at a side of the outer joint member 55, has a cover 66 and a sealing member 67. The cover 66 is generally formed by pressing a steel sheet of SPCC etc. in an annular configuration with a crank shaped cross-section. That is, as shown in an enlarged view of FIG. 6, the cover 66 has a cylindrical portion 66a of larger diameter and a cylindrical portion 66b of smaller diameter. It is fit onto the end 51c of the outer member 51 abutted against the end of the outer member 51.
An outer diameter d1 of the cylindrical portion of larger diameter is set so that it is smaller than an outer diameter D1 of the end portion 51c of the outer member 51 (d1<D1). This enables an inner circumferential edge of the knuckle to be prevented from interfering with the cylindrical portion 66a, of larger diameter, during insertion of the knuckle onto the end portion 51c of the outer member 51.
The sealing member 67 is generally formed of rubber in an annular configuration. It is secured on the cylindrical portion 66b of smaller diameter. Tip ends of a plurality of sealing lips 67a, 67b and 67c are adapted to slidably contact with a cylindrical surface 63a. A stepped surface 63b is formed on a shoulder of the outer joint member 55.
A second cylindrical surface 63c with a diameter smaller than that of the cylindrical surface 63a is formed between the inner raceway surface 55a of the outer joint member 55 and the cylindrical surface 63a. A cylindrical encoder 68 is secured on the second cylindrical surface 63c. The encoder 68 is made of rubber magnetic material with magnetic poles N and S alternately arranged along its circumferential direction. An outer diameter d2 of the encoder 68 is set so that it is smaller than D2 of the cylindrical surface 63a (d2<D2). This enables the encoder 68 to be prevented from interfering with the inner circumferential edge of the sealing member 67 during insertion of the outer joint member 55 into the outer member 51.
A sensor 69 is supported on the cover 66. A flat portion 70 extends along an axial direction of the cover 66. It is formed on the cover at a portion along the circumferential direction of the smaller cylindrical portion 66b of the cover. A radially extending through aperture 70a is formed in the flat portion 70 to mount the sensor 69.
The sensor 69 has a rod shaped inserting portion 69a formed of synthetic resin and a mounting flange 69b arranged at the base end of the inserting portion 69a. A detecting portion is embedded in the tip end of the inserting portion 69a. A wire harness 71, having sufficient flexibility, extends from the base end of the sensor 69.
The inserting portion 69a of the sensor 69 is inserted radially, from outside the cover 66, into the inside of the cover 66 through the mounting aperture 70a. The under side of the mounting flange 69b abuts against the flat portion 70. Under such a condition, the sensor 69 is secured on the cover 66 by a fastening mechanism such as screws. The wheel speed detecting apparatus can be completed by arranging the tip end portion of the inserting portion 69a so that it radially opposes the outer circumferential surface of the encoder 68.
Dimensions of portions relating to the sensor 69 are limited so that the base end portion of the wire harness 71 (shown by a two-dot chain line) does not project radially outward under a condition where the base end portion of the wire harness 71 contacts with the base end surface of the sensor 69. In addition, the position of the sensor 69 can be arranged nearer to the axis of the encoder 68. This reduces the dimension of the outer diameter of the encoder 68. Simultaneously, the dimension of the outer diameter of the cover 66 supporting the sensor 69 can also be reduced.
Accordingly, portions of the seal 60 that include the encoder 68 and the sensor 69 as well as the cover 66 are arranged within a recessed portion opened radially outward between the outer member 51 and the outer joint member 55. Thus, it is possible to detect the rotation of the wheel with high reliability and to reduce the size of the wheel bearing apparatus for a driving wheel having the encoder 68 and the sensor 69 (see Japanese Laid-open Patent publication No. 140146/2005).
In the prior art driving wheel bearing apparatus, the dimension of each portion of the wire harness 71 is limited so that the base end portion of the harness 71 does not project radially outward beyond the end portion 51c of the outer member 51. However, since the wire harness 71 of the sensor 69 sometimes interferes with assembly of the wheel bearing apparatus, it is necessary to insert the outer member 51 into the knuckle with the wire harness 71 being folded. However, this makes the assembly of the wheel bearing apparatus troublesome and thus increases the assembling steps.
In addition, since it is impossible to assemble the wheel bearing apparatus due to interference of the outer joint member 55 with the knuckle after a united connection of the wheel hub 52 and the outer joint member 55, via plastic deformation, it is necessary to previously secure the outer member 51 to the knuckle before the uniting connection of the wheel hub 52 and the outer joint member 55, via plastic deformation. This further complicates the assembly of the wheel bearing apparatus. In addition, this makes it impossible to adopt a system of supplying to an automobile manufacturer with the wheel bearing apparatus as a so-called axle module (a unit of the wheel bearing apparatus, a drive shaft and a constant velocity universal joint at a side of a differential unit (not shown)). Thus, the automobile manufacturer cannot assemble the axle module to the knuckle.
It is, therefore, an object of the present disclosure to provide a wheel bearing apparatus for a driving wheel that improves the workability during assembly by supplying an axle module to an automobile manufacturer.
To achieve the above mentioned object, a wheel bearing apparatus for a driving wheel is provided. It is formed as a unit of a wheel hub, a double row rolling bearing and a constant velocity universal joint. The double row rolling bearing includes an outer member integrally formed, on its outer circumference, with a body mounting flange. The body mounting flange is mounted on a knuckle. The inner circumference of the outer member includes double row outer raceway surfaces. Inner members include a wheel hub and an outer joint member of the constant velocity universal joint. The wheel hub has a wheel mounting flange integrally formed at one end. A cylindrical portion axially extends from the wheel mount flange. The outer circumference of the cylindrical portion has an inner raceway surface corresponding to one of the double row outer raceway surfaces. The outer joint member is formed, on its outer circumference, with another inner raceway surface corresponding to the other of the double row outer raceway surfaces. A hollow shaft portion axially extends from the another inner raceway surface. It is inserted into the wheel hub. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces. Seals are mounted in opening portions of an annular space formed between the outer member and the inner member at its opposite ends. The wheel hub and the outer joint member are integrally connected via plastic deformation. It plastically deforms the shaft portion to caulk it onto the wheel hub. A sensor is radially passed and fit into a mounting aperture formed in the knuckle. A pulser ring is mounted on the outer circumferential surface of the outer joint member. The pulser ring opposes the sensor, via a predetermined radial gap. The outer diameter of the pulser ring is smaller than the inner diameter of the knuckle.
The fourth generation type wheel bearing apparatus for a driving wheel has the wheel hub and the outer joint member united via plastic deformation. A sensor is radially passed and fit into a mounting aperture formed in the knuckle. A pulser ring is mounted on the outer circumferential surface of the outer joint member. It opposes the sensor via a predetermined radial gap. The outer diameter of the pulser ring is smaller than the inner diameter of the knuckle. This wheel bearing apparatus for a driving wheel eliminates troublesome work and improves the workability during assembly. It enables supply, to an automobile manufacturer, of a wheel bearing apparatus as a so-called axle module (a united wheel bearing apparatus, a drive shaft and a constant velocity universal joint at a side of a differential unit). This enables the automobile manufacturer to assemble the axle module to the knuckle.
The pulser ring has an annular supporting member formed by pressing a steel sheet and a magnetic encoder bonded on the annular supporting member. The encoder is formed by an elastomer that is mingled with magnetic powder. It has magnetic poles S, N alternately arranged along its circumferential direction. This makes it possible to reduce the manufacturing cost, weight and size of the wheel bearing apparatus.
The annular supporting member is formed by pressing a stainless steel sheet or a preserved cold rolled sheet. This makes it possible to prevent the generation of rust for a long term. Thus, this improves the durability of the wheel bearing apparatus.
A seal is mounted in an annular space opening formed between the outer member and the outer joint member at its inner side ends. The seal includes an annular sealing plate and a slinger. Each has a substantially L-shaped cross-section and is arranged opposite to each other. The annular supporting member is formed integrally with the slinger. This makes it possible to reduce the number of parts and steps of assembly. Thus, this further improves the workability during assembly.
The sensor is fit in the mounting aperture of the knuckle so that it does not extend beyond the inner diameter of the knuckle. It is retracted from the inner diameter by a predetermined gap. This makes it possible to prevent the magnetic encoder and sensor from being damaged by interference during assembly of the wheel bearing assembly.
The wheel bearing apparatus for a driving wheel is formed as a unit of a wheel hub, a double row rolling bearing and a constant velocity universal joint. The double row rolling bearing has an outer member integrally formed, on its outer circumference, with a body mounting flange. The flange is mounted on a knuckle. The outer member inner circumference includes double row outer raceway surfaces. An inner member has the wheel hub and an outer joint member of the constant velocity universal joint. The wheel hub has a wheel mounting flange integrally formed at one end. A cylindrical portion axially extends from the wheel mounting flange. The outer circumference of the cylindrical portion includes an inner raceway surface corresponding to one of the double row outer raceway surfaces. The outer joint member has, on its outer circumference, the other inner raceway surface corresponding to the other of the double row outer raceway surfaces. A hollow shaft portion axially extends from the other inner raceway surface and is inserted into the wheel hub. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces. Seals are mounted in an annular space opening formed between the outer member and the inner member at their opposite ends. The wheel hub and the outer joint member are integrally connected via plastic deformation. The plastic deformation of the shaft portion caulks it onto the wheel hub. A sensor is radially passed and fit in a mounting aperture formed in the knuckle. A pulser ring is mounted on the outer circumferential surface of the outer joint member. It opposes the sensor via a predetermined radial gap. The outer diameter of the pulser ring is smaller than the inner diameter of the knuckle. Accordingly, it is possible to provide a wheel bearing apparatus for a driving wheel that eliminates troublesome work, improves workability during assembly, and supplies a so-called axle module to an automobile manufacturer. This enables the automobile manufacturer to assemble the axle module to the knuckle.
A wheel bearing apparatus for a driving wheel is formed as a unit with a wheel hub, a double row rolling bearing and a constant velocity universal joint. The double row rolling bearing includes an outer member integrally formed, on its outer circumference, with a body mounting flange. The flange is mounted on a knuckle. The outer member inner circumference includes double row outer raceway surfaces. An inner member includes a wheel hub and an outer joint member of the constant velocity universal joint. The wheel hub has a wheel mounting flange integrally formed at one end. A cylindrical portion axially extends from the wheel mount flange. The outer circumference of the cylindrical portion includes an inner raceway surface corresponding to one of the double row outer raceway surfaces. The outer joint member is formed, on its outer circumference, with another inner raceway surface corresponding to the other of the double row outer raceway surfaces. A hollow shaft portion axially extends from the other inner raceway surface and is inserted into the wheel hub. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces. Seals are mounted in an annular space opening formed between the outer member and the inner member at opposite ends. The wheel hub and the outer joint member are integrally connected via plastic deformation. Plastic deformation of the shaft portion caulks it onto the wheel hub. A sensor is radially passed and fit into a mounting aperture formed in the knuckle. A pulser ring is mounted on the outer circumferential surface of the outer joint member. It opposes the sensor via a predetermined radial gap. The pulser ring includes an annular supporting member formed by pressing a steel sheet. A magnetic encoder is bonded on the annular supporting member. The encoder is formed by an elastomer that is mingled with magnetic powder. It has magnetic poles S, N alternately arranged along its circumferential direction. The outer diameter of the pulser ring is smaller than the inner diameter of the knuckle.